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fvwm-STATES PATENT OFFICE- of Massachusetts, have i inventedcertain new and useful "Improvements, in the `Rolls and Driers of Paper-Machines,l"of which the foli lowing is a full," clear, `and exact description, s reference being had` to the annexeddrawing, ""making a part` of this specication a y "Li The rolls and driers ofpaper machines re'- fquire `certain characteristics which it has s heretofore not been found practicable to atltainfor them tothesdegree of perfection `which is desirable; while the methods by "ylwhichit `is soughtto 4attain these ends, and s `the great time and care bestowed upon `the i manufacture o f therolls and driers, render 1" them exceedingly expensive. Some of the vigrollswork constantly in thev` paper pulp or water, `and must therefore be of a material .u not fragen s which the pulp `or water may contain. `All ofthe rolls,` but someii're than others, require a; perfectly flawless metallic surface, :1"25"".particularly 'ins machines "for making the "Qner "kinds of paper, `while it is necessary i 11 that some offthem; as the press rolls, be of a` "strength that shall enable them to endure the great pressure towhich they are subjected. Various materials have been used, fand different methodsofconstruction em- "ploy'edg all of them, however, have been lia- `[ble to` some objection.` Where iron is used fthe requisitefstiiness and strength is ata tained, butthe castmetal, being fllledwith 1` flaws, produces but an indifferent i surface .even after the apparent defects havebeen I plugged with `great care; For suchrolls and ifdriers as areexposed` to `moisture `and are worked in contact with the `moist paper or felt,iron is very objectionable,owin`g to'its extreme liability to rust, which ,not only soon "destroys the surface of the `roll itself, but, speedily destroysthefelt which `comes in contact with it;` lForsuchrolls a surface ofJ fcopper, bronze,` or other similar fmetallic alloy, is preferred, andfitheyfare usually con:` r structed either by casting malleable copper on `to` ironfounolatlio-ns." When thefmet'hodbf castl ing isado-pted, the requisitestrengthiseasily given tothe press. rolls, but, as `in thecase of the cast iron, such rolls are always more or v hiess unsatisfactory.` The `casting `is never `Mperfect `and the flaws requiretobe bored their places filled with plugs.y ,This

' shrinking hollow cylinde oeiinmniumnaun or Boscroiv', MASSACHUSETTS.

"nenn Aim "ijnrnn Fon` PAPER-MAKING.

`i ssiesaiigajfrettef raient ne, 1214,42, dated February e7, 1855;

expensive, `produces a surface of. very varithe valueoflthe roll, and gives ja less perfect surfaceto thepaper than is produced by a pure deposited metal. i In addition'to these more apparent flaws, the surface of thecast metal is filled with minute imperfections, too small and too numerous to be remedied by plugging, but of sufficient magnitude to leave their impress upon the paper and detract from the finish of its surface. For such rolls as require perfection of surface in union with strength, as in the case of the press rolls, hollow cylinders of copper have been shrunkon to accurately turned iron rolls, but it was found that after being used for a short time, the copper'was rolled out and elongated, there being no union between the two metals to prevent them from sep- `arating, and the plan was abandoned.

`After various experiments I have discovered that all the above objections may be removed, and a perfectly faultless surface produced, by the use of metal deposited by means of voltaic or electric action, 'a metallic cylinder, `of any required strength, being used to receive the deposit. The surface thus produced is without blemish and unequaled `by any surface heretofore produced, the deposited metal being peculiarly adapted to give a superior inishto the surface of the paper, and to resist the action of the water and the'agents which it may contain, while the costof such roll or drier is greatly less than that of the copperor composition rolls and driers now in use. x

`To enable others skilled in the art, to make and use my invention I will proceed toxdescribe the manner in which Ihave carried it out.

A metallic roll is prepared, of dimensions slightly less than those required for the fin' ished roll, and ofa; strength `proportioned to "thefcharacter of the work it has to perform.

The surface ofthe roll is cleansed, in the usual manner, to secure Athe adhesion of the deposited rnetal.` Those parts not intended it repairing and plugging, besides being very sition continued until the required thickness of metal is attained. About three-sixteenths of an inch I have found to answer every purpose,

The accompanying drawing is a View of a paper-machinepress-roll, the dotted line, at a, showing the thickness of the copper coatmg.

Heretofore I have spoken of copperas the material used for covering the rolls and driers, but I do not eonne myself to the use of this metal, as zine, and perhaps other metals, may be employed; and I do not claim the use of any particular metal for the purpose. Neither do I claim the covering of 

